Oops Interview Questions

Object-oriented programming (OOP):

Basic Interview Questions

1. What is object-oriented programming, and how does it differ from other programming paradigms?
2. What are the four basic principles of object-oriented programming?
3. What is encapsulation, and why is it important?
4. What is inheritance, and how is it used in object-oriented programming?
5. Can you explain the difference between abstract classes and interfaces?
6. What is polymorphism, and how is it implemented in object-oriented programming?
7. What is a class, and what are its primary components?
8. Can you explain the difference between a class and an object?
9. What is a constructor, and what is its purpose?
10. What is a destructor, and when is it called?
11. What are access modifiers, and how are they used in object-oriented programming?
12. Can you explain the difference between private, protected, and public access modifiers?
13. What is method overloading, and how is it used in object-oriented programming?
14. What is method overriding, and how is it used in object-oriented programming?
15. What is the difference between a static method and an instance method?
16. What is a singleton class, and how is it implemented?
17. What is a design pattern, and what are some common design patterns used in object-oriented programming?

Advanced Interview Questions.

1. What is a virtual method, and how is it used in object-oriented programming?
2. What is a sealed class, and how is it used in object-oriented programming?
3. What is an abstract method, and how is it used in object-oriented programming?
4. What is an interface, and how is it used in object-oriented programming?
5. What is a property, and how is it used in object-oriented programming?
6. What is a read-only property, and how is it implemented?
7. What is a write-only property, and how is it implemented?
8. What is an index property, and how is it used in object-oriented programming?
9. What is a static class, and how is it used in object-oriented programming?
10. What is a generic class, and how is it used in object-oriented programming?
11. What is a collection, and what are some common collection types in object-oriented programming?
12. What is a LINQ, and how is it used in object-oriented programming?
13. What is an extension method, and how is it used in object-oriented programming?
14. What is a lambda expression, and how is it used in object-oriented programming?
15. What is a reflection, and how is it used in object-oriented programming?
16. What is an exception, and how is it handled in object-oriented programming?
17. What is a stack trace, and how is it used in object-oriented programming?
18. What is a try-catch block, and how is it used in object-oriented programming?
19. What is a finally block, and how is it used in object-oriented programming?
20. What is a namespace, and how is it used in object-oriented programming?
21. Can you explain the concept of polymorphism with an example?
22. What is a dependency injection, and how is it used in object-oriented programming?
23. What is inversion of control, and how is it related to dependency injection?
24. What is a constructor injection, and how is it used in object-oriented programming?
25. What is a property injection, and how is it used in object-oriented programming?
26. What is a method injection, and how is it used in object-oriented programming?
27. What is the SOLID principle, and how is it used in object-oriented programming?
28. Can you explain the Single Responsibility Principle with an example?
29. Can you explain the Open-Closed Principle with an example?
30. Can you explain the Liskov Substitution Principle with an example?
31. Can you explain the Interface Segregation Principle with an example?
32. Can you explain the Dependency Inversion Principle with an example?
33. What is the difference between a value type and a reference type in C#?
34. What is boxing and unboxing in C#?
35. What is the difference between a struct and a class in C#?
36. What is a delegate, and how is it used in C#?
37. What is a multicast delegate, and how is it used in C#?
38. What is a lambda expression, and how is it used in C#?
39. What is a nullable type, and how is it used in C#?